Screen



E. DEISTER Aug. 20, 1929.

S GREEN Filed Dec. 29, 1926 2 Sheets-Sheet INVENTOR. rfit fjetblkr y 24, ALL

A TTORNEY.

Aug. 20, 1929.

E. DEISTER SCREEN 2 SheetsSheet Filed Dec, 29, 1925 INVENTOR. 3 1.1 K ,De(d[ 3r- ATTORNEY.

Patented Aug. 20, 1929.

UNITED STATES 1,725,061 PATENT OFFICE.-

EMIL DEISTEB, OF FORT WAYNE, INDIANA.

SCREEN.

Application filed December 29, 1928. Serial No. 157,654.

.without causing severe stresses thereon at the point or points of connection to the supporting frame; another difficulty is the inability to obtain a vigorous vibratlon of said medium under load without the medium being under excessive tension which introduced additional stresses therein causing frequent fracture thereof especially in the finer mesh mediums, and another difliculty encountered has been the frequent and costly shut-downs of the apparatus for repairsand adjustments due to the excessive wear in the vibrating mechanism.

The object ofm present invention is to provide a screen 0 simple and durable construction in which the difficulties above mentioned are largely minimized if not largely eliminated and which is highly efiicient in sizing materals. j The device is illustrated in the accompanyingr drawings, in which igure 1 is a side elevational view of a screen embodying the invention; Fig. 2 a front elevational view of the same; Fig. 3 a rear elevational view of the same; Fig. 4 a plan view of the screening medium unit; Fig. 5a cross-section on line 55 of Fig. 4; Fig. 6 an enlarged cross-section on line ,66 of Fig. 4; Fig. 7 a front view of one of the rocking connections for the tension bolts; Fig. 8 a cross-section on line 88 of Fig. 7; Fig. 9 a cross-section of the said connection and bolts; Fig. 10 a cross-section of one of the unbalanced pulley and adjustable counterweight units; Fig. 11 a cross-section of said pulley and counterweight unit with the counterweight in the position of maximum vibration; Fig. 12 a side view of the pulley; Fig. 13 a partial cross-section on line 1313 of Fig. 1; Fig. 14 a similar cross-section illustrating two screening mediums; Fig. 15 a plan view of a fraction of the screening medium illustrating the frame engaging means carried-by the medium; Fig. 16 a plan view of the lower end of "one of the frame side members; Fig. 17 a rear elevational view of one of the adjustable legs of the device; Fig. 18 a detail partly in section of the pivotal connection of the leg to the frame; Fig. 19 a plan view of the lower -leg, and

bearing of the front support; Fig. 20 a central cross-section of the same, Fig. 21 a side elevational view of a non-adjustable foot which ma be substituted for the adjustable line 22-22 of Fig. 4.

Referring to the illustrative embodiment of the invention, the main frame 1 of the device comprises two spaced side members 2 and 2 to the upper ends of which are secured the 2 bars 3 and 3. Each side memher is preferably a channel beam, the 2 bars being attached to the lateral flanges of each beam. A shaft 4.- is suitably secured to the lower ends of the side members 2, 2 and the opposite ends of the shaft are free to rotate in the pillow block 5. A bracket 6 is secured to the upper or rear end of each side member 2, 2 and upon the brackets are pivoted the bearing cups 7, each of which cups is formed to receive a cushioning ring 8 preferably formed of rubber, or other suitable material, that is disposed on the conical head 9 secured to or formed on a screw bolt 10.

The screw 10 is loosely engaged in an opening in a boss 11 formed on the base 12, and is locked to the boss in any longitudinally adjusted position by the nuts 13. A shaft 14-. is formed at the lower end of the base, an opening 15 being formed in the base above the shaft so that the cap 16 may be engaged on the shaft and secured to the pillow block 17. The legs each composed of the base 12 and the screw bolt,- are, therefore, pivoted to the frame and to thesu ports so that the rear or upper end of tl e frame may be raised or lowered to secure any desired inclination of the frame. A sleeve 18, formed of suitable material, such as rubber or leather, is inserted between each shaft 4, 14, and its bearings.

Upon the upper side of each side member of the frame is mounted a spring member'19, such as a board of hickory wood. Each member 19 is attached at its op osite ends to the supports 20 that are secure to the side members. Preferably each member 19 tapers somewhat from its middle portion toward each end. To the upper side of the central portion of the members 19 is secured a cross member 21 of suitable material, preferably oak. Two alined ball bearings 22 are .mounted on the member 21 and revolubly support a shaft 23 to which, at suitable points, are keyed two unbalanced pulleys 24 ig. 22 an enlarged cross-section on Each counterweight 25 has a series of apertures formed in one face in any one of which the key 24 will enter. A set screw 25 secures the counterweight to the shaft. In Fig. 10 the heavier side of the counterweight is diametrically opposite the heavier side of the pulley. When the shaft is rotated the pulley and counterweight will now vibrate the cross member 21 a minimum amount. When the counterweight is adjusted to the position shown in Fig. 11 the member 21 will be vibrated the maximum amount. Adjustment of the counterweights to any of the intermediate points will regulate the amount of vibration between the two extremes.

At the forward or lower end of each resilient member 19 I insert a section of rubber or other resilient material 19 between the support 20 and the member 19 and a similar section is inserted between the plate 19 and the top side of the member 19. The nut on the bolt 19 is drawn up lightly so that rattling of the parts is prevented only.

' These resilient connections to the forward ac tive vibration of the members 19.

Two king bolts 26 project through the cross member 21 and through the centralportion of the resilient distributor members 27 that are disposed adjacent to the side members of the frame and are attached respectively to the opposite side edges of the screening medium 28, as hereafter described. Each bolt also is extended through a casting 29 beneath the screening medium and secured thereto.- A guard 27*. is secured to the inner face of each distributor member 27 and rests on the medium 28, the opposite ends of the guard being secured to the posts 29 and .30 respectively. These guards are formed preferably of rubber and prevent the 'material fed to the medium from escaping at the sides of the medium.

Each distributor member 27 is secured to aside edge of the screeningmedium 28. by the bolts 31. The bolts also extend through the screening medium and through one of the cross bars 32, which bars equalize the vibration of the screening medium. The equalizing bars 32 are also secured to the screening medium at intervals by the bolts 33. At each bolt opening 34 (Fig. 6) in each bar,

' a flexible washer 35..is disposed on the bar upon which the medium rests, and by which the medium is spaced from the bar, another similar washer 36 being disposed above the niedilim and a metal washer 37* being disposed on the washer 36. The bolt 33 is passed through the washers, the screening medium and the bar 32,.a nut 37 and lock washer 38 whentightened drawing the parts tect the medium and avoid fracture thereof at the points of attachment to the bars, and

the distributor members and the equalizing bars prevent all whipping of the medium as it is vibrated.

The forward end of the screening medium is curved or bent over a bar or plate 39 that extends across said end of the medium and a plate 40 is placed on the medium and a bar 41'is placed against'the portion of the medium that is beneath the plate 39 and the bolts 42 are passed through alined apertures in the plates and bar and through the medium, suitable nuts on the lower ends of the bolts drawing the parts firmly together. Under the ends of the two plates 39 and 40 are secured the L-shaped castings 43, the rear face 43 of the lateral arm of each casting being curved to pivotally engage a casting 44 that is mounted on the forward end of the side member. The pivotal points of the castings 43 are in the horizontal plane of the screening medium.

Two plates 45 and 46 are similarly secured by the bolts 47 to opposite sides of the screening medium at the rear or upper end thereof. Two or more yokes 48 are secured to the plates and a tension bolt 49 is supported by each yoke and projects rearwardly therefrom. Each bolt is extended through an aperture 50 formed in the Z bar 3 or 3 and through an aperture 51 formed in a lubricant carrying socket member 52 that is secured to the 2 bar. The outer face 53 of the member 52 is concaved and longitudi' nally grooved and it is engaged by the con vexface of member 54 on the bolt. Nuts 55 on the bolt, when tightened against the member 54, place the desired tension on the screening medium, the member 54 pivots on the member 52 when the medium is vibrated just as the forward end of the medium pivots on the castings 44.

When the adjustable leg is not required, I may substitute a support (Fig. 21) for the leg. This support comprises a conical head 56 and a cushioning ring similar to the corresponding parts on the screw 10, the head ing 29" being disposed beneath the medium 28 and the bolts 26 being longer than the bolts 26 so that they will pass through the member 27 and the casting 29 The arm 43 of the plates 43 on the second medium 28 engage in concave sockets 58 formed in the castings 44 that are-secured to the lower ends of the side members 2 and 2*, these sockets being similar to the sockets 58 in which the plates 43 on the upper'medium engage. The tension bolts 49 on the lower medium project through the 2 bar 3* and they are adjusted with respect thereto similarly to the bolts 49 on the upper screen.

The screening medium unit is that shown in Figs. 4: and 5 and it is readily installed on the frame 1 or removed therefrom. The frame may be designed to support any desired number of the screening mediums. WVhen the nuts on the king bolts 26 are tightened the distributor bars 27 are held firmly .against the cross member 21 and the parts below the bar 27 also held firmly in position.

When the shaft 23 is rotated the unbalanced pulleys and the counterweights cause the cross member 21 and the spring board 19 to vibrate. This motion is transmitted by the king bolts and the distributor bars to the screening medium or mediums, the cross bars 32 equalizing the vibrations throughout the medium, so that it is vibrated uniformly inall portions. Since the medium is spaced from the bars 32 the portions thereof between the bolts 33 are freely vibrated and hence are effective to screen the material.

This basket like suspension of the screening medium, formed by the distributor bars and the equalizing bars, holds it rigidly and under control at all times, permitting no whipping of the medium to occur and assuring its positive and vigorous vibration independently of the weight of material being screened and without the necessity of execs sive tension or the possibility of a slack medium. This controlled action of the medium greatly increases its life and the vigorous vibration of the medium in all portions thereof permits large quantities of material of either fine or coarse material to be treated.

The adjustable counterweights on the main shaft permit the adjustment of the vibrations to suit the material being screened, so that it is possible ther eby to obtain a maximum tonnage of material andclose separation thereof on the device.

lVhat I claim is:

1. A vibrating screen consisting of a frame having spaced side members, a screening medium supported in tension on the frame between the side members thereof and means to vibrate the screening medium comprising resilient members mounted on the side members respectively and extending along the same above the screening medium, a cross member secured to the resilient members, means to cause the cross member to vibrate and means rigidly connected to the cross member and to the screening medium.

'2. A vibrating screen consisting of a frame having fixed spaced side members, a screening medium supported in tension on the frame between the side members thereof and means to vibrate the screening medium comprising resilient members extending along the side members respectively and supported thereon, the support at one end of each resilient member being resilient, a cross member above the screening medium engaging and secured to both resilient members, means to cause the cross member to vibrate and means rigidly connected directly to the cross member and to the screening medium.

3. A vibrating screen consisting of a frame having fixed spaced side members, a screening medium supported in tension on the frame and between the said side members thereof and means to vibrate the screening medium comprising spring boards extending along and above the side members respectively, one end of each spring board being rigidly supported on the adjacent side member-and the opposite end thereof be ing resiliently supported on the said side member, a cross member secured at its opposite ends to both spring boards, means to cause the cross member to vibrate and a member rigidly connected to the cross member and to the screening member.

4. A vibrating screen consisting of a fixed frame having spaced side members, spring boards mounted on the top side of the side members respectively and extending along the same, a timber secured at its opposite ends to both spring boards, vibrating mechanism mounted on the timber and adapted to vibrate it, a screeninv medium beneath the timber and supported in tension on the fixed frame and bolts secured at one end to the timber and at their other ends to the, 

